Robert tate



(No Model.)

R. TATB. Hoff AIR PURNAGE.

Patented Oot.fl4," 1892.

UNITED STATES" .,leTENf QFFIQE ROBERT TATE, OF TORONTO, CANADA.

HOT-AIR FURNACE.

SPECIFICATION forming part of Letters Patent No. 483,819, dated October4,1892.

Application filed March 26, 1892. Serial No. 426,515. (No model.)

To @ZZ whom it may concern;

Be it known that I, ROBERT TATE, mannfacturer, of the city of Toronto,county of York, Province of Ontario, Canada, have invented certain newand useful Improvements in Hot-Air Furnaces; and I hereby declare thefollowing to be a full, clear, and exact dcscription of the same.

This invention relates to certain improvements in hot-air furnaces, andmore particularly to the method of introducing cold air into the furnaceand of heating the same; and the object of the invention is to provide ameans for the introduction into the furnace of an auxiliary supply ofcold air, conducting the cold air to the distributing-chamber by way ofthe fire-box and the inner drum, and heating it during its passagetherethrough; and the invention consists, essentially, of forming avertical passage centrally through the inner drum, and connecting to thelower end of this passage the upper end of a curved pipe located withinthe fire-box and extending through the Wall thereof, and connecting tothe lower end of this curved pipe a metallic pipe which extends down tothe base of the furnace within the furnace-casing and passingtherethrough to the outer wall, and connecting to the lower end of thispipe a shaft which extends to the outside of the building. The currentof air enters this shaft and passes through to the pipe within thefurnace-casing, whereit ascends to the curved pipe within the fire-boxand passes therethrough and through the vertical passage formed throughthe inner drum to the distributing-chamber. The airentering the shaft isthe same temperature as the air outside of the building. The instant,however, it enters the pipe within the furnace-casing it is heated byheat radiated fromV the fire-pot and firebOX walls. The air when withinthe curved pipe Within the fire-box is heated by the direct radiation ofthe heat from the lire, and this air ascending to the vertical passagethrough the inner drum is again increased in temperature by theradiation of the heat from the products of combustion circulatingthrough the passage between the walls of this drum on their way to theoutlet of the chimney, the

whole being more fully described in the following specification.

In the drawing the ligure is a perspective view of a furnace,\the outercasing of which and the casing of the drums, fire-box, and firepot arebroken away to show the vertical pas` sage centrally through the innerdrum, the curved pipe connected to thelower end of the vertical passageand extending to the outer wall of the fire box, the metallicconnection-pipe to the base of the furnace, located within thefurnace-casing, the cold-air shaft from the outside of the building,connected to the lower end of the metallic connection-pipe, and thecold-airsupply to the heating-chamber of the furnace from the inside ofthe building.

Like numerals of reference refer to like parts throughout thespecification and drawing.

My furnace consists of an inner drum l, comprised of an outer wall l:Land an inner wall 1b, connected at the top by an annular metallic plate1C. The inner wall lu of the drum 1 composes the casing of the verticalpassage-Way 2, formed centrally through the inner drum 1. The upper endof the vertical passage 2 opens into the distributing-chamber 3 at thetop of the furnace, while to the lower end of the passage is connectedthe top end of the curved pipe 4, located within the fire-box 5. Thelower end of the curved pipe 4 extends beyond the outer wall 6 of thefirebox 5, and to the lower end of the curved pipe 4 is connected theupper end of a nie-- tallic connection-pipe 7, located within thefurnace-casing S and extending to the base of the furnace and beyond thefurnace-casing. Connected to the lower end of the metallicconnection-pipe 7 is one end of a shaft 9, while the other end of saidshaft projects to the outer side of the building, this shaft being shownin dotted lines in the drawing.

As shown by arrows in the drawing, the cold air enters the metallicconnection-pipe 7 from the shaft 9 and passes through the pipe 7 to the95 curved pipe 4, from which it passes to the vertical passage 2 throughthe inner drum l, ascending to the distributing-chamber 3, from whenceit is carried to its respective destinations in the usual manner. Theair when within the shaft 9 is of the same temperature as the airoutside of the building. Vhen, however, it has entered theconnection-pipe 7, it is partially heated by means of heat ra diatedfrom the Walls of the fire-pot 10, and after passing into the curvedpipe 4 it is heated by the direct radiation of the heat from the coalswithin the fire-box 5 and firepot l0. It is during its passage throughthe pipe 4 that the air within the said pipe absorbs the greatest amountof hea't. The air passes from the pipe 4 to the vertical passage 2,where it is again increasedin temperature by the products Yof combustioncirculating through the chamber 11, formed between the inner wall 1b andouter wall 1a. The passage of the air through the pipes 7 and 4 and thevertical passage 2 heats the air to the required temperature before itenters the distributing-chamber 3.

Surrounding the inner drum 1 is an outer drum 12, comprised of an innerwall 12 and an outer wall12b, connected together at their upper andlower ends by means of annular plates 12, and formed between these wallsis a combustion-chamber 12d. A. connection is made between thecombustion-chamber of the inner drum 1 and the combustion-chamber 12d ofthe outer drum 12 by means of a short pipe 13. Between the inlet of thepipe 13 into the combustion-chamber 121 in the outer drum 12 and theoutlet 14 to the chimney is a partition 15 to prevent theshort-circuiting of the products of combustion from thecombustion-chamber 12d in the inner drum to the outlet to the chimney,this partition forcing the products of combustion to complete a travelof almost the entire circuit of the combustion-chamber 12l of the outerdrum before being allowed to escape. By this means it is possible toabsorb a greater percentage of the heat from the products of combustionand utilize the same for heating purposes.

Located at or near the base of the furnace is anopeningintotheheating-chamberformed between the inner wall of the furnace-casing 8and the outer walls of the fire-pot, fire-box, and drums. rThe supply ofcold air passes in through the opening 16 to this heating-chamber and isheated by the heat radiated from the walls of the iire-pot, fire-box,and drums and passes to the distributing-chamber 3, where it unites withthe air heated during its passage through the curved pipe and verticalpassage 2. By a device constructed on this principle it is possible toheat at least thirty-three and a third per cent. more air than could beheated by a furnace of the same size and usingthe same amount of fuelnot provided with a vertical passage through the inner drum andconnections. This vertical passage and connections to the outside of thebuilding insure to the rooms of the building heated a constant supply offresh air direct from the outside and heated to the requiredtemperature. This improvement does not occupy any space that could beotherwise employed; nor does it in any Way interfere with the radiationof the heat and the heating of the cold-air supply taken from theoutside of the building.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is=- 1. In a hot-air furnace, thecombination of an inner heating-drum suspended within thefurnace-casing,averticalpassage-waythrough the inner heating-drum andlocated cent-rally in the same, a distributing-chamber above theheating-drum, into which opens the upper end of the verticalpassage-way, the hre-box located below the heating-drum, a pipe withinthe fire-box, the upper end of which is connected to the lower end ofthe vertical passage-way and the lower end of said pipe projectingbeyond the nre-box Wall, a furnacecasing, a cold-air-supply pipe locatedbetween the furnace-casing and the outer wall of the fire-box, the upperend of the cold-air-supply pipe connected to the lower and outer end ofthe pipe within the fire-box, a cold-air-supply shaft connected to thecold-air-supply pipe7 and a passage between the furnace-casing and theouter Walls of the fire-box and heating-drum, leading to thedistributingchamber, substantially as described.

2. In a hot-air furnace, the combination of the inner heating-drumsuspended withintheV Vheated by the radiation of the heat from the wallsof the fire-pot and the bent pipe adapted to be heated by the radiationof the heat from the fire within the fire-box, a cold-airsupply shaftconnected to the cold-air-supply pipe entering the heating-chamberbetween the furnace-casing and the walls of the firepot, the fire-box,and the heating-drum, substantially as described.

Toronto, March 15, 1892.

R. TATE.

In presence of-m CHAs. H. RIcHns, M. E. ANGELL.

IOO

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